In recent years there has been an increasing research effort aimed at using organic materials as semiconductors rather than the traditional inorganic materials such as silicon and gallium arsenide. Among other benefits, the use of organic materials may enable lower cost manufacturing of electronic devices, may enable large area applications, and may enable the use of flexible substrates as supports for electronic circuitry in display backplanes, integrated circuits RFID tags, and sensors.
A variety of organic semiconductor materials have been considered, the most common being fused aromatic ring compounds as exemplified by acenes. At least some of these organic semiconductor materials have performance characteristics such as charge-carrier mobility, on/off current ratios, and sub-threshold voltages that are comparable or superior to those of amorphous silicon-based devices. These materials have often been vapor deposited since they are not very soluble in most solvents. When organic semiconductors have been deposited from solution (such as in a solution with an organic solvent), good or optimum performance characteristics have been difficult to achieve.
U.S. Pat. No. 6,690,029 B1 purportedly discloses certain substituted pentacenes and electronic devices made therewith.
WO 2005/055248 A2 purportedly discloses certain substituted pentacenes and polymers in top gate thin film transistors.
U.S. patent application Ser. No. 11/275,366 filed Dec. 28, 2005, the disclosure of which is incorporated herein by reference, generally discloses an all-inkjet printed thin film transistor and methods of making and using same. The following references may be relevant to inkjet printing of organic semiconductors: Lim et al, “Self-Organization of Ink-jet-Printed Triisopropylsilylethynyl Pentacene via Evaporation-Induced Flows in a Drying Droplet,” Adv. Funct. Mater., 2008, 18, pp. 229-234.
Some report using unusual device geometries with organic semiconductor materials, e.g. concentric ring or Corbino geometries. The following references may be relevant to such a technology: Klauk et al., “Pentacene Organic Thin-Film Transistors for Circuit and Display Applications,” IEEE Transactions on Electron Devices, Vol. 46, No. 6, June 1999, pp. 1258-1263; Meijer et al., “Dopant density determination in disordered organic field-effect transistors,” J. App. Physics, Vol. 93, No. 8, 15 Apr. 2003, pp. 4831-4835.
U.S. patent application Ser. No. 11/275,367, filed Dec. 28, 2005, the disclosure of which is incorporated herein by reference, generally discloses thin film transistor with bottom-gate geometry and methods of making and using same.
U.S. Provisional Pat. App. No. 61/057,715, filed May 30, 2008, the disclosure of which is incorporated herein by reference, generally discloses silylethynyl pentacenes, compositions containing silylethynyl pentacenes, and methods of making and using silylethynyl pentacenes, e.g. as organic semiconductors.
U.S. Provisional Pat. App. No. 61/060,595, filed Jun. 11, 2008, the disclosure of which is incorporated herein by reference, generally discloses the use of mixed solvent systems for deposition of organic semiconductors.
U.S. Provisional Pat. App. No. 61/076,186, filed Jun. 27, 2008, the disclosure of which is incorporated herein by reference, generally discloses methods of growing organic semiconductive layers; methods of fabricating organic semiconductor devices; and layers and devices formed thereby.